| dc.description.abstract | One of the most reversible, potent and selective phosphodiesterase-5 (PDE-5) inhibitors, which has been used for the treatment of erectile dysfunction (ED) is tadalafil (6R,12aR) - 2, 3, 6, 7, 12, 12a- hexahydro- 2- methyl- 6- (3, 4- methylenedioxyphenyl) pyrazino (1_,2_:1,6)- pyrido (3, 4-b) indole-1, 4- dione. Being a widely-encountered male sexual dysfunction, ED can be defined as the persistent or recurring inability to attain and/or maintain penile erection for satisfactory sexual intercourse. It causes extensive adverse effects on the both physical and the psychological health of men and even, on their partners. ED affects an estimated 150 million of the male population between the ages of 40 and 70 in the worldwide. Diabetes mellitus, atherosclerosis, obesity and comorbidities of hypertension may result in ED. Also, alcoholism, use of illicit drugs, cardiovascular disease and some pharmacologic agents such as diuretics, ?-blockers and antidepressants play a significant role in the etiology of ED. PDE-5 inhibitors have high tolerability and perfect efficacy. Also, these inhibitors have been frequently abused to produce counterfeited ED medicaments in industrialized countries. Among the PDE-5 inhibitors, tadalafil (Eli Lilly), sildenafil citrate (Pfizer) and vardenafil hydrochloride (Bayer) were approved by the Food and Drug Administration (FDA). The commercial brandmarks of these inhibitors, namely Cialis®, Viagra®, and Levitra®, are used to treat ED disorders. PDE-5 inhibitors are commonly sold as both illegal additives in herbal dietary supplements and counterfeited medicines on the internet. Active pharmaceutical ingredients analysis is very important to create preliminary safety and therapeutic efficacy of drug candidates for further detailed research. This chapter describes different analysis techniques including spectrometry, chromatography and electrochemistry used quantitatively and qualitatively to determine tadalafil from pharmaceutical dosage forms, biological samples or other samples. In this chapter, there are selected studies from recent years. Also, the advantages or disadvantages of methods, analysis conditions, applications and validation parameter results were mentioned for analyzing tadalafil in the pharmaceutical dosage forms and natural samples. © 2020 Nova Science Publishers, Inc. All rights reserved. | en_US |
